"What was the purpose of these first two days of school and what are my plans for this year?"
In the first day of school, we did The Marshmallow Chalenge. We needed to balance the marshmallow up 20 spaghetti and one string.
In the second day of school, Ms.Silva gave the instructions about the way we are going to work this year.
My plans for this year is, to have a good grades, learn more about science and improve my english.
MEALS ON WHEELS
In our science projects, we had to analyze 3 different menus, and talk about what each menu had. Each member of the group was responsable for one part of the projects, mine was the introduction. We had to choose one menu for a short term diet, and another for a long term one, so we could see the difference between them. For this, we had to research about the nutrients found and used in each one of the menus. In my opinion the best menu was the second, because it was balanced in terms of nutrients, proteins and others.
I like to be Prokaryotic cell, because the Prokaryotic cell has few internal structure that are distinguishable under a microscope. The prokaryotic is unicellular. Unicellular is an organism that consists of only one cell.Although some of these organisms live in colonies, they are still unicellular. These organisms live together, and each cell in the colony is the same. Most of the bacterias are prokaryotics, and some bacterias are important to our lifes.
In this project, each person needed to research about one cell, and present why you think that your cell is important. But each group had one captain in order to say wich was the best presentation (I was one capitan). In my opinion the best explanation was the Cell Wall. The person said: "In additiona to that, no only does the cell wal protect the cell from water, but also from pathogens. Furthermore,in a leaf`s case, in order ro increase the photosynthetic capacity, the cell wall helps the plant cell keep up with its shape and by this, because of the plant cell`s rectangular, the close packing of these cells will leave no space left. Also,in order for a plant to grow and develop, the cell wall helps a plant cell to communicate with other plant cells. For that, the cell wall has the plasmodesmata, which allows encoded information molecules to pass between plant cells." This was the presentation in wich the person gave the best explanation about her research.
EGG LAB!
INTRODUCTION:
We made an experience with a egg to know more about Osmosis and Diffusion. The object of this investigation is to see in real terms about Osmosis and Diffusion.
In group we put a egg in a cup with 80ml of alcohol, and other egg in a cup with 85ml of syrup. We observed the difference between mass, volume and circunference during tree days.
RESULTS:
The egg in the alcohol was smaller than the egg in the syrup.Both of the eggs suffered changes everyday. Some got smaller but with more mass. We can see some of the results in the dates that were collected:
TABLE: The analyze of the egg in the alcohol and syrup.
We can see the graph bellow:
We can see that the mass decrease in the alcohol, but increase in the syrup. This mean that the egg got havir in the syrup.
WHY?
This happen because, the syrup is more concentrated than the egg, and the syrup absorved the egg, they change places between each other. This fenomeno is called OSMOSIS.
In the alcohol was different, because the alcohol mixtured with the egg (went inside the egg). The egg got "hard", because it permeate with the alcohol. We could see everyday that the alcohol was vanishing. This fenomino is called DIFFUSION.
All living things have certain requirements they must satisfy in order to remain alive. This include exchanging gases, minerals, food and others.
In my group,I think that didn't have a source of error, all the procedure went well.
EVALUATE TEAM:
Everybody work together, helping each other. We had no problems.
EVALUATE WHAT I LEARNED:
It's easier to understand the process of Osmosis and Diffusion when you see this happening.
Cells Final Project!
My project goal: my goal was to get more knoweledge about what we learned in science classes. My Plan: How can we learn and have fun at the same time? Playing a GAME. This is the reason of my project. I thought that a game could be a fun and easy way to learn more about cells. I used the game "Perfil" as a model to my science game.
In the last 3 week, I worked on my project in class and at home. We needed to create a table to show how we were working.
I didn't have to make any changes in my project. This was my first idea. You can see the rules of the game on the video:
Self Evaluation: I think that I work hard in this project. And in the end was what I did expect.
A new semester just began. It`s time to start to work again. In the first week of class we started learning about electricity and how it works in a more scientific way. Ms.Silva gave us a list of 8 goals, for us to be guided. The list is: EM1. I can explain how eletric charges interact. first I can say that the interaction between electric charges is called ELETRICITY. The interaction of eletric charges happens with electrons (-) and protons (+) because they have opposite charges. The interaction happens when you put charged objects, with opposites charges or not, close to one another. In this process occur the ELECTRIC FIELD, that it is a region around a charged object where it happens attraction or repulsion of other object. http://www.mundoeducacao.com.br/fisica/campo-magnetico.htm
EM2. I can give examples of how charges can be transferred between materials and explain them. Charges are not created nor destroyed, they are transfered. There is 3 ways of transference: Friction - is a transference of electrons from an object without charge (stactic object, that is no moving, no changing. The charges are equal) to another object. Ex: when you rub a feet with socks on the carpet floor. Conduction - is a transference of electrons from an object with charge to another. Ex: when you step on the floor with socks and the socks touches the skin. Induction - is the moviment of electrons from one part of an object to another, the objects produces an eletric field so they repel. Ex: when you touch a doorknob with a finger.
EM3. I can explain how an electric current is produced. It's produced when electric charge is constructed to flow through a wire or similar material. In this circut we will have different voltages. The voltage is a difference of electric energy`s potential between two places in a circuit.
EM4. I can compare conductors with insulators. Conductor is the material through wich electric charge can flow, usually the materials used in the conductors are metalic, and the metal is a very good conductor. And insulators is a material through wich electric charge will not flow easily, because the insulators are usually made of non metalic materials, and the electric currents will be insignificant.
EM5. I can explain how resistance affects current. Its the measure of the difficulty that the charges have to flow in a material. The greater the resistance, the less current. There are some factors that affects the resistance:
- the length of the conductor, because the longer the conductor more resistance will be.
- the cross - sectional of the conductor, because wider conductors will have a greater cross - sectional are.
- the material that a conductor is made of. Not all materials are good conductors.
EM6. I can use Ohm's law to calculate resistance, current or voltage.
Ohm`s law deals with the relationship between VOLTAGE and CURRENT in an ideal conductor. This relationship shows that:
- the potential difference (voltage) across an ideal conductor is proportional to the current through it.
- the resistance is a constant (do not change).
- Ohm`s law is represented by: RESISTANCE = VOLTAGE : CURRENT
- Ohm`s law can be used to solve simple circuit. A complete circuit is one which is a closed loop. It contains at least one source of voltage and at least one potential of drop (a place where the potential energy decreases).
- An increase of potential energy in a circuit causes a charge to move from lower to higher potential.
EM7. I can build series and parallel circuits and describe its parts. http://www.allaboutcircuits.com/vol_1/chpt_5/2.html
Series Circuit: all the parts of an electric circuit are connected one after another along one path.
Here a battery and the three resistors are connected by a single wire in series with each other. http://www.physics247.com/physics-tutorial/parallel-circuits.shtml
Parallel series: the different parts of a circuit are on separete paths. Resistor are connected by a separete path from the battery and back to the battery.
EM8. I can explain the relationship between power, voltage and current.
The relationship between them happens when the energy is transformed into another form. Ex: a hair dryer transform eletric energy to thermal energy. This happens because the power of the hair dryer depends on voltage and current. You can calculate power by using this formula: POWER = VOLTAGE X CURRENT.
Our challenge for these weeks is to build a motor using the subjects that we are learning. Ms.Silva suggested that we make a research in the internet to see examples for us to meke our motor. I found many examples, some was more complicated, some was more simple, and some I didn't have all the materials. I found a simple motor in terms of materials but one that illustrated very well some concepts that we learned. In my motor I had to use the following materials:
- 1 battery (1.5 volts)
- 1 nail
- 1 magnetic
- 1 wire.
I will give you a brief information about how to do the motor for it works correct:
Connect the wire to the battery (-side), it's better to use a tape to keep it connected because the wire gets warm.
Put the magnetic on the botton of the nail.
Put the top of the nail on the other side (+side) of the battery. Bring the wire close to the magnetic and the nail will start to rotate.
It was very simple to do and amazing to see the results. In the case of my motor the wire works as the conductor, the electric charge did flow through it and in contact with the magnetic made the nail to rotate.The magnetic was used to keep the nail plugged in the battery, and the charge that comes to the wire passes through the magnetic to the nail. I had no insulators in this motor, the charge did flow easily. it also didn't have much resistance, because the conductor was a metal wire and metal wire have electrons that are loosely held to their atoms.
I never thought that would be so great to see a production of electric current in a such simple way.
You can see my motor working in the video bellow:
In the begining of this semmester I had many difficulties to understand all those subjects. I had to read the book and the notes many times, in order to understand all those things.
I summarized everything and all the subjects did became more clear for me, because I studied more, I started to think in the subjects in my day to day, for example: electrical appliance transformes electrical energy into another form, I could see this the hair dryers, and many others things. Now I started to understand the voltage, that its the electric energy's potential (in Brazil, we have 110V and 220V), and I feel more confident now.
I guess its all for awhile, I will continue reading more in order to have a good and productive semester.
More Learning Goals
EM9. I can describe the properties and interactions of magnets
More than 2000 years ago people in the Ancient Greek city of magnesia, found a different rock that contained a mineral called magnetite. Now a days this pieces of magnetites are also called magnets.
The magnets have the same properties as magnetite that is to attract iron and other materials that contain iron. Another propertie of the magnetism is to attract or repel other magnets and in addition one part of magnet will always point north when swing freely.
The interactions between magnets it depends on how you hold the poles of the magnets. With the properties to attract iron materials, we realized that the capacity of attraction is concentrated in two points of the magnets called poles. Recalling that one end of a magnet always points north, the other end is called south pole. If you bring the north pole of a magnet close to a south pole of another, they will attract one another. The opposite happens if you bring two north or two south poles near each other they will move away or repel each other. http://www.splung.com/content/sid/3/page/magnetism
EM10. I can describe how the magnetic domains are arranged in a magnetic/non-magnetic material
To understand the arrangement in a magnetic/non-magnetic materials, we need to know the definition of magnetic domain. Magnetic domain is a grouping of atoms that have their magnetic field aligned with one another.
The entire domain acts like a bar magnet with a north pole and a south pole.
The direction in with the domain will point indicates if the material is magnetic or non-magnetic.
When you have a non-magnetic materials, that is materials with non iron, the magnetic domain will point in random directions.
When you have a magnetic material, the ones that is made of iron or contain iron, the magnetic domain will point in the same direction, we can say that all or most of the domains are arranged in the same direction.
A material that has strong magnetic properties is called ferromagnetic material.
EM11. I can explain the connection between electricity and magnetism (electromagnetism)
The discovered of Oersted was essential to unify electricity and magnetism. This relationship is called ELECTROMAGNETISM. Everywhere that there is electricity, there is magnetism. An eletric current produces and electric field.
Oersted during an experiment put a compass needle near to a wire with current, he observed that the needle changed direction, whenever he produced a current in a wire, the compass needle align around the wire.
This experiment showed that magnetism and eletricity are related.
EM12. I can outline the difference between DC/AC current and its uses
The difference between DC/AC is that:
AC is an alternating current that flows in both directions and DC is direct current that flows in only one direction; the product that is flowing is electrons.
The AC power is what supplies our homes. The wires outside our houses are connected at 2 ends to AC generators. The DC is found in batteries and solar cells.
EM13. I can explain why the Earth behaves like a magnet and the consequences of it
In the late 1500s, Sir William Gilbert an English physician became interested in studying the compass and why it always pointed to same direction. After many research he got the conclusion that a compass behaves as it does because Earth acts as a giant magnet and has a magnetic field surrounding it and has two magnetic poles.
In the geographic earth`s north pole there is the magnetic south pole of the planet and with the geographic south`s pole of the earth there is the north pole of the planet.
The consequences is that Earth produces a strong magnetic field that extends to space, this magnetic field affects the movements of electrically charged particles on space. One of those electrically charged particles come from the sun. When solar wind hits the earth, the waves of radiation crashed the magnetosphere changing the intensity and the direction of Earth`s mantic field. For us we can feel this consequences as a fall of electricity, malfunction of satellites and etc.
The Auroras is another consequence that happens when high speed charged particles get close to Earth`s surface.
In this case the consequence is something beautiful to see, the aurora is a curtain of shimmering bright light in the atmosphere.
EM14. I can explain the importance of grounding wires and using fuses/circuit breakers
A grounding wire happens when a charge is able to flow directly from the current into Earth in the event of a short circuit.
Fuse is a device that contains a thin strip of metal that will melt if there is too much current through it.
They are both used as circuit breakers when current gets too high, overloading a circuit can result in fire.
EM15. I can explain how an electromagnet works and cite applications for them
An electromagnet is a strong magnet in with the magnetic field is produced by the flow of electric current. This strong magnet can be turned on and off.
Electromagnets can be used to record information in videotapes, computers, credo card and etc.
We can`t forget that, many other devices, such as motors, generators and a simple door bell use electromagnets.
EM16. I can explain how a simple motor works (parts and function)
An electric motor transforms electrical energy into mechanical energy. This is also a good example of the application of the Oerted`s experiment in which the electric current is associated to a magnetic field and can provoke the movement of a magnetic.
A simple motor works basically by using an electric current in a magnetic field to produce motion or to put something in movement.
We have 2 kinds of motors, motors with alternating current AC and motors with direct current DC. Parts of a motors:
Brushes: the brushes that touch the commutator conduct current to the armature. The brushes do not move.
Armature: The current is in opposite directions on each side of the armature causing one side to move up while the other side moves down.
Commutator: The commutator rotates with the armature. The direction of current reverses with each half turn so the armature spins continuously.
EM17. I can describe how a generator and a transformer work
A generator is used to transform mechanical energy into electrical energy. We can say the a generator is the opposite of an electric motor. A generator see motion in a magnetic to produce an electric current.
We have two kind of generators, the AC and DC.
Transformer is used to increase or decrease voltage for example to transmit electrical energy generated by electric companies that is transmitted over long distance we need high voltage. In our home, electrical energy is used at much lower voltages. So what makes the changes in this voltages of electrical charges is the transformers. We can also use transformers in some devices in our homes that requires higher voltages such as tv, fluorescent lights etc. This devices contain step-up transformers. Other devices that need lower voltage such as electronic games, door bell etc has a step-down transformers. http://www.gcsescience.com/pme23.htm http://www.gcsescience.com/pme25.htm
EM18. I can explain the importance of transformers to power grids
Let`s look at the electricity that comes to our home. When electricity moves from a power plant it is put into a very high voltage to be able to travel long distances. In order for our home or store to use the electricity, it has to be at a lower voltage than on the long - distance lines. So the electricity is "stepped - down" to a lower level using a transformers. In our neighborhood we have many transformers on top of a utility pole, or connected to underground wires. EM19. I can explain methods of power production and distribution
The electric companies uses giant generators to produce most of he electrical energy we use in our home and school. But nested of using a crank to supply the mechanical energy, a turbine is used.
We have many way of power production;
the hydropower where the normal water cycle is used to generate other form of energy (electricity)
the solar where the sun is the only source of energy and the solar power can be caught by solar plants and transformed in electrical energy
wind by using windmills that can transfer the energy of the air through electricity
nuclear that is used dangerous and toxic materials to generate electricity.
The power distribution in the final stage. A distribution system`s network carries electricity form the transmission system and delivers it to the consumers.
EM20. I can describe the differences of 110v/220v and main advantages and disadvantages of each
Once more using Ohm`s law where RESISTANCE = VOLTAGE/CURRENT we can say that a voltage of 220V sofers less resistance than a 110V .
Resistance is the loos of energy while the electrons path though a conductor. The higher voltage, lower resistance.
The advantages and disadvantages are many such as:
in case of electric shock the 110V is less dangerous for the person because the voltage is lower.
to use a 220V source is a good way to prevent over charge.
the maintenance for the substation is less expensive for 220V because will need less transformers
the amount we pay it is the same for both 110V and 220V
EM21. I can describe the advantages and disadvantages of electrical energy
Electrical energy is the most common form of energy used in houses and industry. Advantages:
It can be easily converted to other form of energy
It is much cheaper than other forms of energy
It can be easily transmitted to many locations efficiently
This form of energy can be controlled and monitored easily.
"What was the purpose of these first two days of school and what are my plans for this year?"
In the first day of school, we did The Marshmallow Chalenge. We needed to balance the marshmallow up 20 spaghetti and one string.In the second day of school, Ms.Silva gave the instructions about the way we are going to work this year.
My plans for this year is, to have a good grades, learn more about science and improve my english.
MEALS ON WHEELS
In our science projects, we had to analyze 3 different menus, and talk about what each menu had. Each member of the group was responsable for one part of the projects, mine was the introduction. We had to choose one menu for a short term diet, and another for a long term one, so we could see the difference between them. For this, we had to research about the nutrients found and used in each one of the menus. In my opinion the best menu was the second, because it was balanced in terms of nutrients, proteins and others.What kind of cell would you like to be and why?
I like to be Prokaryotic cell, because the Prokaryotic cell has few internal structure that are distinguishable under a microscope. The prokaryotic is unicellular. Unicellular is an organism that consists of only one cell.Although some of these organisms live in colonies, they are still unicellular. These organisms live together, and each cell in the colony is the same. Most of the bacterias are prokaryotics, and some bacterias are important to our lifes.http://library.thinkquest.org/C004535/prokaryotic_cells.html
Lifeboat Dilemma
In this project, each person needed to research about one cell, and present why you think that your cell is important. But each group had one captain in order to say wich was the best presentation (I was one capitan). In my opinion the best explanation was the Cell Wall. The person said: "In additiona to that, no only does the cell wal protect the cell from water, but also from pathogens. Furthermore,in a leaf`s case, in order ro increase the photosynthetic capacity, the cell wall helps the plant cell keep up with its shape and by this, because of the plant cell`s rectangular, the close packing of these cells will leave no space left. Also,in order for a plant to grow and develop, the cell wall helps a plant cell to communicate with other plant cells. For that, the cell wall has the plasmodesmata, which allows encoded information molecules to pass between plant cells." This was the presentation in wich the person gave the best explanation about her research.EGG LAB!
INTRODUCTION:We made an experience with a egg to know more about Osmosis and Diffusion. The object of this investigation is to see in real terms about Osmosis and Diffusion.
In group we put a egg in a cup with 80ml of alcohol, and other egg in a cup with 85ml of syrup. We observed the difference between mass, volume and circunference during tree days.
RESULTS:
The egg in the alcohol was smaller than the egg in the syrup.Both of the eggs suffered changes everyday. Some got smaller but with more mass. We can see some of the results in the dates that were collected:
TABLE: The analyze of the egg in the alcohol and syrup.
We can see the graph bellow:
We can see that the mass decrease in the alcohol, but increase in the syrup. This mean that the egg got havir in the syrup.
WHY?
This happen because, the syrup is more concentrated than the egg, and the syrup absorved the egg, they change places between each other. This fenomeno is called OSMOSIS.
In the alcohol was different, because the alcohol mixtured with the egg (went inside the egg). The egg got "hard", because it permeate with the alcohol. We could see everyday that the alcohol was vanishing. This fenomino is called DIFFUSION.
All living things have certain requirements they must satisfy in order to remain alive. This include exchanging gases, minerals, food and others.
In my group,I think that didn't have a source of error, all the procedure went well.
EVALUATE TEAM:
Everybody work together, helping each other. We had no problems.
EVALUATE WHAT I LEARNED:
It's easier to understand the process of Osmosis and Diffusion when you see this happening.
Cells Final Project!
My project goal: my goal was to get more knoweledge about what we learned in science classes.
My Plan: How can we learn and have fun at the same time? Playing a GAME. This is the reason of my project. I thought that a game could be a fun and easy way to learn more about cells. I used the game "Perfil" as a model to my science game.
In the last 3 week, I worked on my project in class and at home. We needed to create a table to show how we were working.
I didn't have to make any changes in my project. This was my first idea.
You can see the rules of the game on the video:
Self Evaluation: I think that I work hard in this project. And in the end was what I did expect.
My QUIZ!!!
https://docs.google.com/spreadsheet/viewform?formkey=dHhpWXVPdi1QdzZVUkp3M1kzNDNvTEE6MQ#gid=0
My Motor.
A new semester just began. It`s time to start to work again.In the first week of class we started learning about electricity and how it works in a more scientific way. Ms.Silva gave us a list of 8 goals, for us to be guided. The list is:
EM1. I can explain how eletric charges interact.
first I can say that the interaction between electric charges is called ELETRICITY. The interaction of eletric charges happens with electrons (-) and protons (+) because they have opposite charges. The interaction happens when you put charged objects, with opposites charges or not, close to one another. In this process occur the ELECTRIC FIELD, that it is a region around a charged object where it happens attraction or repulsion of other object.
http://www.mundoeducacao.com.br/fisica/campo-magnetico.htm
EM2. I can give examples of how charges can be transferred between materials and explain them.
Charges are not created nor destroyed, they are transfered. There is 3 ways of transference:
Friction - is a transference of electrons from an object without charge (stactic object, that is no moving, no changing. The charges are equal) to another object. Ex: when you rub a feet with socks on the carpet floor.
Conduction - is a transference of electrons from an object with charge to another. Ex: when you step on the floor with socks and the socks touches the skin.
Induction - is the moviment of electrons from one part of an object to another, the objects produces an eletric field so they repel. Ex: when you touch a doorknob with a finger.
EM3. I can explain how an electric current is produced.
It's produced when electric charge is constructed to flow through a wire or similar material. In this circut we will have different voltages. The voltage is a difference of electric energy`s potential between two places in a circuit.
EM4. I can compare conductors with insulators.
Conductor is the material through wich electric charge can flow, usually the materials used in the conductors are metalic, and the metal is a very good conductor. And insulators is a material through wich electric charge will not flow easily, because the insulators are usually made of non metalic materials, and the electric currents will be insignificant.
EM5. I can explain how resistance affects current.
Its the measure of the difficulty that the charges have to flow in a material. The greater the resistance, the less current. There are some factors that affects the resistance:
- the length of the conductor, because the longer the conductor more resistance will be.
- the cross - sectional of the conductor, because wider conductors will have a greater cross - sectional are.
- the material that a conductor is made of. Not all materials are good conductors.
EM6. I can use Ohm's law to calculate resistance, current or voltage.
Ohm`s law deals with the relationship between VOLTAGE and CURRENT in an ideal conductor. This relationship shows that:
- the potential difference (voltage) across an ideal conductor is proportional to the current through it.
- the resistance is a constant (do not change).
- Ohm`s law is represented by: RESISTANCE = VOLTAGE : CURRENT
- Ohm`s law can be used to solve simple circuit. A complete circuit is one which is a closed loop. It contains at least one source of voltage and at least one potential of drop (a place where the potential energy decreases).
- An increase of potential energy in a circuit causes a charge to move from lower to higher potential.
EM7. I can build series and parallel circuits and describe its parts.
http://www.allaboutcircuits.com/vol_1/chpt_5/2.html
Series Circuit: all the parts of an electric circuit are connected one after another along one path.
Here a battery and the three resistors are connected by a single wire in series with each other.
http://www.physics247.com/physics-tutorial/parallel-circuits.shtml
Parallel series: the different parts of a circuit are on separete paths. Resistor are connected by a separete path from the battery and back to the battery.
EM8. I can explain the relationship between power, voltage and current.
The relationship between them happens when the energy is transformed into another form. Ex: a hair dryer transform eletric energy to thermal energy. This happens because the power of the hair dryer depends on voltage and current. You can calculate power by using this formula: POWER = VOLTAGE X CURRENT.
Our challenge for these weeks is to build a motor using the subjects that we are learning. Ms.Silva suggested that we make a research in the internet to see examples for us to meke our motor. I found many examples, some was more complicated, some was more simple, and some I didn't have all the materials. I found a simple motor in terms of materials but one that illustrated very well some concepts that we learned.
In my motor I had to use the following materials:
- 1 battery (1.5 volts)
- 1 nail
- 1 magnetic
- 1 wire.
I will give you a brief information about how to do the motor for it works correct:
Connect the wire to the battery (-side), it's better to use a tape to keep it connected because the wire gets warm.
Put the magnetic on the botton of the nail.
Put the top of the nail on the other side (+side) of the battery. Bring the wire close to the magnetic and the nail will start to rotate.
You can see in the picture how it is done.
http://physicslessons.com/mmotor12.gif
It was very simple to do and amazing to see the results. In the case of my motor the wire works as the conductor, the electric charge did flow through it and in contact with the magnetic made the nail to rotate.The magnetic was used to keep the nail plugged in the battery, and the charge that comes to the wire passes through the magnetic to the nail. I had no insulators in this motor, the charge did flow easily. it also didn't have much resistance, because the conductor was a metal wire and metal wire have electrons that are loosely held to their atoms.
I never thought that would be so great to see a production of electric current in a such simple way.
You can see my motor working in the video bellow:
In the begining of this semmester I had many difficulties to understand all those subjects. I had to read the book and the notes many times, in order to understand all those things.
I summarized everything and all the subjects did became more clear for me, because I studied more, I started to think in the subjects in my day to day, for example: electrical appliance transformes electrical energy into another form, I could see this the hair dryers, and many others things. Now I started to understand the voltage, that its the electric energy's potential (in Brazil, we have 110V and 220V), and I feel more confident now.
I guess its all for awhile, I will continue reading more in order to have a good and productive semester.
More Learning Goals
EM9. I can describe the properties and interactions of magnetsMore than 2000 years ago people in the Ancient Greek city of magnesia, found a different rock that contained a mineral called magnetite. Now a days this pieces of magnetites are also called magnets.
The magnets have the same properties as magnetite that is to attract iron and other materials that contain iron. Another propertie of the magnetism is to attract or repel other magnets and in addition one part of magnet will always point north when swing freely.
The interactions between magnets it depends on how you hold the poles of the magnets. With the properties to attract iron materials, we realized that the capacity of attraction is concentrated in two points of the magnets called poles. Recalling that one end of a magnet always points north, the other end is called south pole. If you bring the north pole of a magnet close to a south pole of another, they will attract one another. The opposite happens if you bring two north or two south poles near each other they will move away or repel each other.
http://www.splung.com/content/sid/3/page/magnetism
EM10. I can describe how the magnetic domains are arranged in a magnetic/non-magnetic material
To understand the arrangement in a magnetic/non-magnetic materials, we need to know the definition of magnetic domain. Magnetic domain is a grouping of atoms that have their magnetic field aligned with one another.
The entire domain acts like a bar magnet with a north pole and a south pole.
The direction in with the domain will point indicates if the material is magnetic or non-magnetic.
When you have a non-magnetic materials, that is materials with non iron, the magnetic domain will point in random directions.
When you have a magnetic material, the ones that is made of iron or contain iron, the magnetic domain will point in the same direction, we can say that all or most of the domains are arranged in the same direction.
A material that has strong magnetic properties is called ferromagnetic material.
EM11. I can explain the connection between electricity and magnetism (electromagnetism)
The discovered of Oersted was essential to unify electricity and magnetism. This relationship is called ELECTROMAGNETISM. Everywhere that there is electricity, there is magnetism. An eletric current produces and electric field.
Oersted during an experiment put a compass needle near to a wire with current, he observed that the needle changed direction, whenever he produced a current in a wire, the compass needle align around the wire.
This experiment showed that magnetism and eletricity are related.
EM12. I can outline the difference between DC/AC current and its uses
The difference between DC/AC is that:
AC is an alternating current that flows in both directions and DC is direct current that flows in only one direction; the product that is flowing is electrons.
The AC power is what supplies our homes. The wires outside our houses are connected at 2 ends to AC generators. The DC is found in batteries and solar cells.
EM13. I can explain why the Earth behaves like a magnet and the consequences of it
In the late 1500s, Sir William Gilbert an English physician became interested in studying the compass and why it always pointed to same direction. After many research he got the conclusion that a compass behaves as it does because Earth acts as a giant magnet and has a magnetic field surrounding it and has two magnetic poles.
In the geographic earth`s north pole there is the magnetic south pole of the planet and with the geographic south`s pole of the earth there is the north pole of the planet.
The consequences is that Earth produces a strong magnetic field that extends to space, this magnetic field affects the movements of electrically charged particles on space. One of those electrically charged particles come from the sun. When solar wind hits the earth, the waves of radiation crashed the magnetosphere changing the intensity and the direction of Earth`s mantic field. For us we can feel this consequences as a fall of electricity, malfunction of satellites and etc.
The Auroras is another consequence that happens when high speed charged particles get close to Earth`s surface.
In this case the consequence is something beautiful to see, the aurora is a curtain of shimmering bright light in the atmosphere.
EM14. I can explain the importance of grounding wires and using fuses/circuit breakers
A grounding wire happens when a charge is able to flow directly from the current into Earth in the event of a short circuit.
Fuse is a device that contains a thin strip of metal that will melt if there is too much current through it.
They are both used as circuit breakers when current gets too high, overloading a circuit can result in fire.
EM15. I can explain how an electromagnet works and cite applications for them
An electromagnet is a strong magnet in with the magnetic field is produced by the flow of electric current. This strong magnet can be turned on and off.
Electromagnets can be used to record information in videotapes, computers, credo card and etc.
We can`t forget that, many other devices, such as motors, generators and a simple door bell use electromagnets.
EM16. I can explain how a simple motor works (parts and function)
An electric motor transforms electrical energy into mechanical energy. This is also a good example of the application of the Oerted`s experiment in which the electric current is associated to a magnetic field and can provoke the movement of a magnetic.
A simple motor works basically by using an electric current in a magnetic field to produce motion or to put something in movement.
We have 2 kinds of motors, motors with alternating current AC and motors with direct current DC.
Parts of a motors:
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EM17. I can describe how a generator and a transformer work
A generator is used to transform mechanical energy into electrical energy. We can say the a generator is the opposite of an electric motor. A generator see motion in a magnetic to produce an electric current.
We have two kind of generators, the AC and DC.
Transformer is used to increase or decrease voltage for example to transmit electrical energy generated by electric companies that is transmitted over long distance we need high voltage. In our home, electrical energy is used at much lower voltages. So what makes the changes in this voltages of electrical charges is the transformers. We can also use transformers in some devices in our homes that requires higher voltages such as tv, fluorescent lights etc. This devices contain step-up transformers. Other devices that need lower voltage such as electronic games, door bell etc has a step-down transformers.
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EM18. I can explain the importance of transformers to power grids
Let`s look at the electricity that comes to our home. When electricity moves from a power plant it is put into a very high voltage to be able to travel long distances. In order for our home or store to use the electricity, it has to be at a lower voltage than on the long - distance lines. So the electricity is "stepped - down" to a lower level using a transformers. In our neighborhood we have many transformers on top of a utility pole, or connected to underground wires.
EM19. I can explain methods of power production and distribution
The electric companies uses giant generators to produce most of he electrical energy we use in our home and school. But nested of using a crank to supply the mechanical energy, a turbine is used.
We have many way of power production;
- the hydropower where the normal water cycle is used to generate other form of energy (electricity)
- the solar where the sun is the only source of energy and the solar power can be caught by solar plants and transformed in electrical energy
- wind by using windmills that can transfer the energy of the air through electricity
- nuclear that is used dangerous and toxic materials to generate electricity.
The power distribution in the final stage. A distribution system`s network carries electricity form the transmission system and delivers it to the consumers.EM20. I can describe the differences of 110v/220v and main advantages and disadvantages of each
Once more using Ohm`s law where RESISTANCE = VOLTAGE/CURRENT we can say that a voltage of 220V sofers less resistance than a 110V .
Resistance is the loos of energy while the electrons path though a conductor. The higher voltage, lower resistance.
The advantages and disadvantages are many such as:
EM21. I can describe the advantages and disadvantages of electrical energy
Electrical energy is the most common form of energy used in houses and industry.
Advantages:
Disadvantages: